\[{{}_{2}\phi_{1}}\left({q^{-n},b\atop c};q,z\right)=\frac{\left(c/b;q\right)_{n%
}}{\left(c;q\right)_{n}}{{}_{3}\phi_{2}}\left({q^{-n},b,bzq^{-n}/c\atop bq^{1-%
n}/c,0};q,q\right).\]